Buttonhole-sewing machine



Dec. 15, 192sa 1.565.241 E. B. ALLEN BUTTONHOIJE SEWING MACHINE Filed 0G11. 9. 3924 6 Sheets-Sheet 1 Dec. 15, 11925. 1,565,241 E. B. ALLEN BUT'roNHobE SEWING MACHINE Filed Oct. 9. A1924 6 Sheets-Sheet 2 NVENTOR TNE SES MTORNEY E. E. ALLEN' BUTTONHOLE SEWING MACHINE 1924 6 Sheets-Sht 3 INVENTOR ATTORNEY E. B. ALLEN BUTTQNHOLAE SEWING MACHlN y Filed om. 9.

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E. B. ALLEN BUTTONHOLJ SEWING MACHINE Filed ci.. 9, 1924 Sheets-Sima?, 5

@ INVENTOR @E EN 'jm` WITNECSUSES BY ATTORNEY Dec. l5 ,1925.

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4 uw NM1 EG. LN. L19 Awa. .SC EEO .nd EMM wm.. T T U B Patented Dec. 15, 1925.

UNITED STATES PATENT OFFICE.

EDWARD B. ALLEN, GF NEWTOWN, CONNECTICUT, ASSIGNOR TO THE SINGER MANU- FACTURING COMPANY, OF ELIZABETH, NEW 3ERSEY, .A CORPORATION OF NEW JERSEY.

BUTTONHOLlE-SEWING- MACHINE.

Application filed October 9, 1924. Serial No. 742,507.

To @ZZ whom t may concern.'

Beit known that I, EDWARD B. ALLEN, a citizen oi' the United States, residing at Newtown, in the county oi Fairfield and State of Connecticut, have invented certain new and useful Improvements in Buttonhole- Sewing Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

rlihis invention relates to buttonhole sewing machines of the type commonly embodying stitch-forming mechanism, a stop-motion device for controlling its period of action, a work-holder and stitch-positioning mechanism for relatively moving the stitch-forming mechanism and work-holder to sew around a buttonhole. Machines of' the type in question are commonly employed for sewig eyelet-end buttonholes, and the stitch-positioning mechanism of such machines commonly includes means for rotating the stitch- 'forming mechanism 180 in sewing around the eye-end of the buttonhole. Such machines have also been used for sewing a square bar across the end ott a buttonhole by the provision or' means for stopping the stitchilorming mechanism at the end of the second side-stitching operation while the, stitchiiorming mechanism is being rotated through a 'further angle of 90, after which the stitchforming mechanism is again started and sews the bar squarely across the end of t-he buttonhole; the stitch-forming mechanism being started and stopped twice for each buttonhole-producing cycle. Such machines have also been fitted for sewinO' straight (as distinguished from eyelet-end) buttonholes, by the provision of means for stopping the stitch-forming mechanism at the end of the tirst side-stitching operation and while the stitch-lorming mechanism is being rotated i800, after which the stitch-forming mechanisin is again started and sews the second side ci the buttonhole; the stitch-forming mechanism being, in this case also, started and stopped twice for each buttonhole-producing cycle. The need ifor starting and stopping the stitch-'forming mechanism twice 'lor cach buttonhole-producing cycle, while the stitch-forming mechanism is being idly rotated, doubles the wear and tear on the stop-motion device, which already has a heavy duty to p crjlio-rin, and nbjectitmably limits the quantity of work which can be produced per day per machine.

Heretofore, in the work producedby an eyelet-end buttonhole machine, the ratio of the number of eye stitches to the number of side stitches is fixed and determined by the contours oli' the several synchronously moving stitch-positioning cams. The spacing or the eye stitches cannot be changed by adjustment of the feed of the stitch-positioning` cams, wit-hout also changing the spacing of the side-stitches, and vice-versa. To meet the requirements of the trade, there isl need ior a machine having provision for varying the spacing of the stitches at the eye-end or the buttonhole independently of the spacing of the side stitches.

I have disco-vered a means whereby the above described short-comings of prior machines may be remedied and a smoothly and rapidlyV running and more versatile machine produced. According to the present improvement the machine is provided with means for automatically changing the speed of the stitch-positioning mechanism during a portion of the sewing period without stopping the stitch-forming mechanism. When such means is constructed and timed to automatically increase the speed of the stitchpositioning cams while sewing around the eye-end of a buttonhole, the result will be an increase in the spacing and a reduction in the number of the stitches placed in the eye. By increasing the speed of such cams sufiiciently at this time the number of eyestitches may be reduced to Zero, i. e., the stitch-forming mechanism may be rotated 1800 in one stitch-forming cycle and the machine caused to sew a straight buttonhole without the necessity of starting and stopping the stitch-forming mechanism twice per buttonhole-producing cycle. Speed-changing means ot the character Vin question may also be used to quickly turn the stitch-forming mechanism of a buttonhole sewing machine through an angle of at the end of the second side-stitching operation to posi- `tion it for stitching a square-bar across the end ot the buttonhole; the speed-changing means enabling the stitch-forming mechanism to continue its sewing action uninterruptedly and making it unnecessary to start and stop the stitch-forming mechanism .twice per buttonhole-preducing cycle, as has heretofore been necessary to produce a square barred buttonhole.

The invention is preferably embodied in a buttonhole sewing machine of the type disclosed in the patent to Allen, llo. 15,324, reissued Aprilul, 1922, and, as so embodied, comprises an additional driving connection between the sewing shaft and the stitchpositioning mechanism, which additional driving connection is normally ineffective but is automatically rendered effective during apredetermined stage of the 'stitching period,.to more rapidly drive the stitchpositioning mechanism than it Would othervvise normally be driven. The additional driving connection may conveniently be constituted by a lateral crank-shaft geared to the sewing shaft and operating a reciprocating pawl arranged to engage a ring mounted on or forming a part of the usual pattern-Wheel at the side of the machine bed. The major portion of the ring` engaged by such pawl, is smooth, so that, although the payvl rests upon the ring, it reciynocates idly. Such ring, however, is formed at the desired point with one, tivo or a series of teeth, depending upon the character of the vvork which it is desired to produce. lilhen the pawlvencounters the toothed portion of the periphery of the ring, it drives the pattern-wheel ahead with one` or more impulses and thereby increases the speed of the stitchpositioningmechanism until the toothed portion of such ring is driven beyond the field of action of the pawl, whereupon the stitch-positioning mechanism resumes its normal speed. The effective stroke of the pawl may be adjusted to secure any desired feed of the stitch-positioning mechanism.

Referring to the accompanying drawings, Fig. 1 is a right side elevation of a buttonliole sewing machine embodying the invention. Fig. 2 is a left side elevation of the machine. Fig. 3 is a bottom plan view. Fig. 4lis a horizont-al sectional view through the machine bed showing elements of the stitch-positioning mechanism in plan. Fig. 5 is a rear end-elevation, partly in section, of the machine. Fig. 6 is a vertical section taken transversely of the machine bed substantially along the line 6, 6, Fig. 3. Fig. 7 is a fragmentary inside elevation of the latch mechanism which controls the rapid feed clutch. Fig. 8 is a development ofthe lateral-feed cam-groove in the pattern-Wheel at the side of the machine bed. Fig. 9 is a fragmentary side elevation of the crank driven reciprocating pawl mechanism, used for increasing` the speed of the stitchpositioning mechanism Without stopping the stitch-forming mechanism. Fig. l() is a similar view showing how elements of the mechanism may be shifted to permit removal of the patternvvheel. Fig. 11 is a perspective view of the pawl guiding bracket shown in Fig. 10. Fig. 1Q is a bottom plan view of the feed-wheel shown horizontally in section in Fig. (i. F ig. 123 is a top plan view of the adjustable crank-driving element for the reciprocating pawl above referred to. Fig. la is a section on the line 14, 1.4, Fig. 13, and Fig. 15 is a diagrammatic plan View ofva square-bar buttonhole produced by the machine illustrated in F i gs. 1 to 1st inclusive.

The invention is illustrated as embodied in an eyeletsend buttonhole sewing machine constructed substantially in accordance with the disclosure of the Allen reissued patent previously referred to. Such a machine is formed with a frame including a hollov.' rcetangular bed 1, standard 2 and b racket-arm 3 terminating in the head si..

rthe stitch-forming mechanism is preferably constructed substantially in accordance with the disclosure of the Allen et al. Patent No. 1,312,473, of March 22, 1921, and comprises the reciprocating and laterally jog- KV 'ng needle 5 and loop-taking mechanism b' carried by the usual upper and lovfcr rotary supports actuated synchronously by the upper and lower sector gears 7, 8 which are connected by means of the links f), to the arms 11, 12 fixed to the vertical shaft 13,

The lovver arm l2, Fig. 4, carries a foilovfer roll let entering the usual stitch-forming mechanism rotating canrgroove 15 in the feed-Wheel 1G. The needle is connected to be driven as usual from the vertical shaft 17, Fig. 1, geared at 18 to be driven by and at the same speed as the sewing shaft 1S) which latter is connected at its forward end to drive the loop-taker mechanism 3; the needle being given tivo reciprocations per revolution of the'sewing shaft if), one for the depth-stitchand one for the slit-stitch.

The Work-holder or Work-clamp and its actuating mechanism are constructed substantially in accordance with the disclosure of said reissued patent. The vforkmiiam!) comprises the usual upper and lower clamping elements Q0, 21 which are mounted for travelling movements over the bed l under the influence of the feed-levers 22, 23, Fig. fi, Which are actuated, respectively, by the longitudinal and lateral feed cam grooves 24, 25 in the feed-wheel 16.

As disclosed in said reissued patent, the lateral feed-lever 23 is coupled by means of the vertically sliding and downwardly spring-pressed coupling bolt 26, Fig. 2, to the lever 27 which at its forward end carries a block 28 entering` the slideway 2S) of the cross slide-plate 3() of the workholder. The coupling bolt 26 has fixed thereto a lateral linger-piece 31 which projects through the inverted L-shaped slot 32 in the boss 33 at the rear end of the lever 2T. When the linger-piece 31 rests at the lil() lli@ bottom end of the vertical portionlof the inverted L-shaped slot 32, asv shown in Fig. 2, theupper end of the coupling bolt 26 is clear of the actuating lever 23 and the lower end of such bolt projects into a supplementary lateral feed-cam groove 34 in the pattern-wheel 35 removably secured to the transverse shaft 36 which is connected by means of the one-to-one gears 37 to the feedwheel 16. f

The cam-slot 34 in the pattern-wheel 35 is, in the particular machine illustrated, provided with a filler-block 38 to eject the slide-bolt 26 from the cam-groove 34 and project the upper end of said bolt into the aperture in the free end of the lever 23, thereby transferring the control of the lateral position of side-shift movements of the work-clamp from the pattern-wheel 35 to the main feed-wheel 16 during the sewing of the eyel'et-end of the buttonhole. After the eye has been sewn, the bolt 26 drops back in the cam-groove 34 and the latter resumes control of the lateral position of the work-holder during the remainder of the sewing period.

rlhe synchronously moving feed and pattern-wheels 16, 35 having the several cam-grooves and connections for shifting the work-holder and turning the stitch-forming mechanism, constitute the stitch-positioning mechanism of the machine. This mechanism is normally driven by the step-by-step moving star-wheel 39 which is engaged by the diametrically opposed pins 4() carried by the vertical shaft 17. The star-wheel 39 is connected through thev train of gears 41, Fig. 4, to the gear-ring 42 carried by the feed-wheel 16. The gear-ring 42 is formed internally with ratchet-teeth 43, Fig. 12, which are engaged by the pawls 44-mounted on' the feed-wheel 16. The ratchet-teeth 43 andpawls 44 constitute a one-way driving connection between the gear-ring 42 and the feed-wheel 16; such connection permitting the feed-wheel to be driven by other means at a faster speed than it is driven by thepin and star-wheel drive.,

The machine is provided with the usual rapid-feedmechanism for driving the feed and pattern-wheels between sewing periods, to shift the work from cutting to sewing position, and vice versa, and for reversely turning the stitch-forming mechanism to restore it to initial position at the end of the sewing period. As more fully disclosed in said `reissued patent and in my copending application Serial No.` 537,381, filed February 18, 1922, the rapid feed mechanism comprises the usual continuously running shaft 45 having the worm 46 which meshes with the gear 47 connected to the live element 43 of a clutch connection between the The .driven element 49 `bf the clutch connection is fixed to the shaft 36. Driving relation is established between the driving and driven clutch elements 48, 49 by means of the clutch-controlling cone 50, Fig. 3, which is shifted by the arm 51 carried by the endwise slidable shaft 52. The mechanism for sliding the shaft 52 in opposite directions to start and stop the rapid-feed comprises the two continuously reciprocating bars 53, 54, Fig. 6, and their controlling latches 55, 56, Fig. 7. The latch 55 is shifted to release the rapid-feed starting bar 53 by means of the arm 57 fast on the rockshaft 58 on which are also fixed the armsand 60, Fig. 1. The arm 59 is depressed to start the rapid-feed prior to sewing by the downwardly extending arm 61 of the usual clamp-closing lever 62. The arm is raised to start the rapid-feed, subsequent to sewing, by the latch-arm 63 which is carried by the horizontal lever 64 influenced by vertical motion of the stopping tooth 65 on the block 66 which slides on the stop-motion lever 67. The rapid-feed is stopped by means of the usual tripping points 68, Fig. 7 on the pattern-wheel 35; such points-rocking the lever 69 and swinging the latch 56 to release the declutching bar 54.

The stop-motion lever 67, Fig. 2, which controls the starting and stopping of the sewing shaft 19 is rocked by the arm 79 and link connection 79 to the lever -7 1 fulcrumed at 72 on the machine frame and having a follower nose 73 riding on a peripheral cam-track 74 on the patternwheel 35. As disclosed in my said cepending application the link includes the toggle element 75 which may be swung to dotted line position, Fig. 10, to withdraw the nose 73' from the cam-track 74 and render the stop-motion control inoperative.

The machine is provided with the buttonhole cutters 7 6, 77 carried by the usual cutter-levers which are operated from the cutter-shaft 73, as disclosed in said reissued. patent.

The present improvement comprises means for changing the speed of the stitchpositioning mechanism during the sewing.

To this end I have provided the machine 1 herein illustrated and constructed otherwise substantially in accordance with the disclosures of said reissued patent and pending application, with an additional train of driving connections for the stitch-positioning mechanism; such additional drive being actuated bythe sewing shaft 19.

The sewing shaft 19 has fixed thereto a bevel-gear 79, Fig. 3, with which meshes in one-to-one relation a similar gear 8L) l fixed to the transverse shaft 81 j'ournaled in the bearing sleeve 81l fixed to the bed 1. The shaft S1 has fixed to its outer end. a craiik-disk 32, Figs. 13 and 14, formed with an undercut radial slot 33 to which is fitted the head 84 of the crank-pin S5. The crankpin 85 passes through the sleeve 86 and is threaded at its outer end to receive the nut 87 by which the sleeve 86 and head 84 are tightly clamped to the crank-disk 82. By loosening the nut 87 the crank-pin and sleeve 86 may be shifted along the slideway 83 to secure any desired eccentricity of the crank-pin relative to the shaft 81. Journaled on the sleeve 86 is the rearward end of the two sectioned'pawl-bar 88 of adjustable length.A The front end 89 of the pawlbar rests upon the toothed ring 90 which is mounted on the pattern-wheel In. the machine illustrated, which is designed to sew a square-bar buttonhole, the ring 90, Fig. 9, has a single tooth 91 and has an otherwise smooth periphery on which the end 89 of the pawl-bar rests under the influence of the spring 92. The pawl-bar 88 reciproeates idly upon the toothed ring 90 during the sewing of the first side 91, Fig. 15, eyelet-end 92 and second side 93 of the buttonhole. lVhen the sewing reaches the end 94 of the second side of the buttonhole, the end 89 of the pawl-bar, on the retracting stroke of the latter, drops over the tooth 91, Fig. 9, and on the advance of the pawl-bar the pattern-wheel and feedwheel 16 are fed ahead at higher speed than the pin and star-wheel actuated ring 42 on the main feed-wheel 16; the ratchet-teeth 43 and pawls 44 on-the gear-ring 42 and feed-wheel 1G permitting the increased spoed to be imparted to the stitch-positioning mechanism.l at this time.

rlhe feed-wheel 16 is turned through an angle a, Fig. 12, by one stroke of the pawlbar 88 executedl during one-half revolution of the sewing shaft, and the stitch-forming mechanism is quickly rotated 99o, mainly while the needle is out of the work, by the curved portion of the cam-slot 15 lying within the angle a which is several times as large as the angle l) through which the feed-wheel is turned per half revolution of the sewing shaft 19 by the pin and starwheel drive 39, 40. It would be impracticable, without increasing the speed 4of the feed-wheel 16,` to rotate the stitch-forming mechanism through any considerable angle, such as 90o within the period of one reciprocation of the needle 5, as the eccentric portion of the cam-slot 15 lying Within the angle a would have to be condensed to lic within the much smaller angular portion l) of the feed-wheel and would be too abrupt to be operative. Hence, by increasing the speed or throw of the feed-wheel at this time, suicient motion may be imparted to rotate the stitch-forming mechanism 90O without cutting the cam-slot 15 too abrupt to be practically operative.

After the stitchforming mechanism has been rotated 90, the pawl-bar 88 becomes inelfectiveand the pin and star-wheel or normal drive of the feed-wheel 16, through the gear-ring 42, is resumed during the sewing of the square-bar 95, Fig. 15. The irregular portion of the cam-slot 34 lying between the lines cl and e, Fig. V8, controls the side shift movements of the work-holder during the sewing of the square bar 95. The abrupt change in the direction of sewing, from the second side 93 of the buttonhole to the square-bar 95, is made without stopping the stitch-forming mechanism and hence without loss of time.

By referring to Figs. 2, 9, 10, 11, it will be noted that the pawl-bar 88 extends between the tines 96 of the fork member 97 Xed to the lever 71. When the toggle section 7 5 of the bar 7 O is shifted to dotted line position, Fig. 10, to withdraw the nose 73 of the lever 71 from the stop-motion controlling cam 74 on the pattern-wheel 85, the fork-member 97 swings to dotted line position and lifts the pawl-bar 88 clear of the pattern-wheel so that the latter may be readily removed for substitution of another' pattern-wheel for making a buttonhole having different characteristics.

The sewing of a straight buttonhole without stopping the stitch-forming mechanism at the end of the first side-stitching operation, while the stitch-forming mechanism is being turned 1800, can beaccomplished by providing a machine such as illustrated in said reissued patent with the present pawlbar feed and with a pattern-wheel having a straight lateral feed-controlling groove which has no filler block 38 and no side throws. Such pattern-wheel may be provided with a toothed ring similar to the ring 90 but having its single tooth so placed as to be encountered by the pawl-bar at the completion of the sewing of the rst side of the buttonhole. The crank-pin 85 should be shifted sufficiently far from the center of the shaft 81 to impart to the pawl-bar an impulse of suflieient amplitude to turn the pattern-wheel and feed-wheel 16 through the angle c, Fig. 12, which, through the usual eccentric portion of the cam-slot 15 within such angle, effects the 180o turn of the stitch-forming mechanism at a single sweep.

The present pawl feed mechanism may also be applied to a machine such as illustrated in said reissued patent to enable a change to be effected in the number of stitches in the eye of the buttonhole independently of the number of side stitches. To effect this result the pattern-wheel is provided with a toothed ring similar to the ring 90 but having a series of teeth equal in numberyto the reduced number of depth stitches which it is desired to place around the eye. This series of teeth is formed in an angular portion of the pattern-wheel' equal to the angle c and is timed so that the first tooth of the series is engaged by the pawl-bar at the beginning' of the semicircular eye-stitching operation. The stroke of the pawl-bar is reduced so as to feed the pattern-wheel ahead one tooth at a time and thus effect the desired spacing of thedepth stitches. The forward or feeding stroke of the pawl-bar 88 is timed to be executed simultaneously with the impulse imparted to the star-wheel 39 by one of the pins 40. This impulse imparted to the star-wheel 39 at this time is ineffective, however, since it turns the-toothed ring 42 through an angle less than the angle through which the feedwheel is turned by the impulse of the pawlbar. On the recovery stroke of the pawlbar, however, the other pin 40 imparts a normal feeding impulse to the feed-wheel. Thus, while sewing the eye, the feed-wheel receives impulses alternately from the pawlbar 88 and one of the pins 40, the former being of increased amplitude. The result is the desired increased spacing of the stitches around the eye of the buttonhole.

Having thus set forth the nature of the invention, what I claim herein is* l. A buttonhole sewing machine having in combination, stitch-forming mechanism, a work-holder, stitch-positioning cams making one complete rotation per buttonhole producing cycle and connections for relatively rotating and feeding` the stitch-forming mechanism and work-holder to sew around a buttonhole, means connected to the sewing shaft for driving said stitch-positioning cams at a normal speed during a portion of the period of action of the stitchforming mechanism, and means for more rapidly driving said cams during another portion of the period of action of the stitchforming mechanism while the latter continues its sewing action, said last-named means including an accessibly located controlling wheel and means for driving said cams through said wheel.

2. A buttonhole sewing machine having in combination, a hollow bed, stitch-forming mechanism, a work-holder, stitch-positioning cams making one complete rotation per buttonhole producing cycle and connections for relatively rotating and feeding the stitch-forming mechanism and work-holder to sew around a buttonhole, means connectedI to the sewing shaft for driving said stitchpositioning cams at a normal speed during the period of action of the stitch-forming mechanism, and means for more rapidly driving said cams during a portion of the period of action of the stitch-forming mechanism while the latter continues its sewing action, said last-named means comprising a cross-shaft disposed transversely of the machine bed, a toothed controlling wheel removably mounted on said cross-shaft eX- ternally of the machine bed, a third shaft disposed transversely of the machine bed and driven by the sewing shaft, a crank on said third shaft, and a pawl connected to be reciprocated by said crank and engaging said toothed controlling wheel.

3. A buttonhole sewing machine having, in combination, stitch-forming mechanism, a sewing shaft, a work-holder, stitch-positioning mechanism for relatively moving the stitch-forming mechanism and work-holder to sew around a buttonhole, and a plurality of trains of actuating connections between said stitch-positioning mechanism and the sewing sha'i't, one of which trains includes a one-way driving connection adapted to drive the stitch-positioning mechanism during a buttonhole-producing cycle and the other of which is adapted to drive said mechanism at a higher speed during a portion of a buttonhole-producing cycle.

Li. A buttonhole sewing machine having, in combination, stitch-forming mechanism, a work-holder, stitch-positioning cams making one complete rotation per buttonholeproducing cycle and connections for relatively moving the stitch-forming mechanism and work-holder into and out of sewing relation and for relatively rotating and feeding the stitch-forming mechanism and workholder to sew around a buttonhole, a rapidfeed drive for actuating said cams during the relative movement of the stitch-forming mechanism and work-holder into and out of sewing relation, a sewing-feed drive for actuating said cams during the sewing of the buttonhole, and a third drive for increasing the speed of said cams during a portion of the sewing period.

5. A buttonhole sewing machine having, in combination, stitch-forming mechanism, rotary supporting means therefor, a workholder, means for relatively feeding the stitch-forming mechanism and work-holder, and means for rotating the stitch-forming mechanism through an angle of at least 90 at one end of the buttonhole during a period of one stitch-forming cycle and without stopping the stitch-forming mechanism.

6. A buttonhole sewing machine having, in combination, stitch-forming devices, rotary supporting means therefor, a workholder, means for relatively feeding the stitch-forming devices and work-holder, mechanism for rotating the stitch-forming devices when the sewing reaches one end of the buttonhole, and a reciprocating pawl and connections for imparting an impulse to said mechanism by a single stroke of said pawl suflicient to rotate the stitch-forming mechanism through an angle of at least 90o without stopping the stitch-forming mechanism.

In testimony whereof, I have signed my name to this specification.

IEDVARD B. ALLEN.

CII 

